Automatic fire-alarm



(No Model.)

T. F. ROBINSON 8v 1?. SMITH.

AUTOMATIG FIRE ALARM.

Patented Oct. 5

TENT n w/ T/VE 5555;

. lof the device. the plunger.

with their points into the connected in the usual UNITED ST TEs PATE T O FICE.

THOMAS FREDERICK nonINsoN AND vimntuons SMITH, or LITTLE (FALLS,

' NEW YORK.

AUTOMATIC FIRE-ALARM. I

pass through the screws when a contact. is simultaneously established'with the pointsof the screws bymeans of a conductor. D represents a plunger which is slidabl r it 11mg, concrnL- f that we, THOMAS FREDERICK FRANCIS SMITH,

To all whom Be it known v hollow portion of the useful Ims' in Automatic Fire-Alarms, of which the following is a specification.

spiral spring E, which is interposed between the piston'and the said reduced hollow portion of the base-plate, and is adapted to exert a pressure upon the piston. of the piston is made conical may easily adj nst itself into contact with the projecting ends or points of the screws B when the plunger is forced towardthem. v F represents a pin or stopper capable of being 'bent, hroken, fused, or practically destroyed' when exposed to a predetermined temperature. This pin extends first through a staple G, secured to the front side of the base-plate; and then through a hole D in the pl e plunger back against the tension of the spiral spring and of the piston from coming in contact with the points of the screws. In amount of projection of the pin in the hole f the plunger, the pin is provided with a head F, which engages the staple when the desired limit of 'PI'OJGCiLiOD has been reached.

inorder that it,

invention consists-essentially, in ajde-= vice which will automatically close the circuit in an electric alarm system when the'surrounding temperature sh parts. Fig. 2 is a similar view'of. the device,- showing the position of the parts as they appear when the surrounding. temperature has reached a predeterminedpoint. Fig. 3 is a plan View Fig. 4 is an elevated view of Similar letters refer to similar parts throughout the diiferent views.

A represents the base-plate of the device, preferably made of wood or, some other insulating material. This base-plate is adapted to be attached to the wall or ceiling by means of four screws A-, and is provided with a centrally-located. hollow portion A. This hole wedged between the plunger and the reduced hollow portion of the base-plate, the forward portion of the plunger is reduced. This reduced portion terminates in a knob Dfiwhich described. g,

B represents two binding-posts provided with two screws B, which are screwed in to opposite sides of the said base-plate and extend hollow portion A 0 represents two conducting-wires leading he electric alarm-system- The selwi'res are 9 manner tothe bind-- e electric current to end portion contact ingposts and permit t The end portion and is adapted to normally hold the 7 order to limit the and pulling the pl ung'er out, so that the hole of the same will be situated in line with the opening: formed by the staple,.iu which position the pin is first pushed through the staple and then the end portion of the pin inserted in the hole of the plunger.- a h 7e are aware that many changes may be made'in the construction of our improved firealarm, and for that reason do not desire to limit ourselves to the particularconstruction herein shown and described, but reserve the right to make such changes as would fairly come within the scope of our invention.

Having thus described our invention, what we claim as new and desire to secure by Let ters Patent, is-

In an automatic fire-alarm, the combination with the insulating" base-plate, said base-plate being provided with a centrally-located hollow portion, the forward end of said portion being reduced so as to form a square shoulder, two conductors, forming part of an electrio alarm system, extending into said hollow portion, a plunger'sl idably mountedin said hollow portion, said plunger being provided at its rear end with a piston having a lo11gitudinal guiding-surface and a conical end portion, a spiral spring interposed between the piston and the said shoulder in the hollow portion of the base-plate, the forward portion of the. said plunger being reduced and terminating in a knob, a hole extending through the thick portion of the plunger ad- ,iaceut to the reduced portion thereof, a pin capable of being destroyed when exposed to a predetermined temperature, partly extending through said hole, said pin being provided with an enlarged portion or head, a staple or guide located on the front surface of the baseplate, engaging said head of the pin, substantially as described and for the purpose set forth. I

itness our hands this 1 8th day of January,

THOMAS FREDERICK ROBINSON. FRANCIS SMITH.

Witnesses I IVAN T. BURNEY,

J. B. hICGUIRE. 

